BACKGROUND: Although exposure to tobacco smoke has been associated with increased morbidity and mortality, cigarette smoking is still common in the asthmatic population. Induced sputum neutrophilia has been observed in asthmatic smokers, but the effects of regular smoking on their bronchial mucosa morphology remain to be defined. This study documents the inflammatory and remodelling features in bronchial biopsies of smoking compared with non-smoking asthmatics. METHODS: We analysed bronchial biopsies from 24 steroid-naïve young subjects with mild asthma: 12 non-smoking and 12 currently smoking subjects. In addition to airway morphology assessment, inflammation and remodelling were analysed by immunohistochemistry using antibodies against CD3, CD68, major basic protein, neutrophil elastase, and tryptase. Expression of the cytokines IL-4, IL-5, IL-8, IFN-gamma, transforming growth factor-beta, and TNF was determined by in situ hybridization. RESULTS: Compared with non-smoking asthmatic subjects, smoking asthmatics' bronchial mucosa showed squamous cell metaplasia, in addition to increased expression of subepithelial neutrophil elastase, IFN-gamma, and intraepithelial IL-8. CONCLUSIONS: Smoking status modifies morphological and inflammatory processes in young subjects with mild asthma. The changes may possibly affect asthma treatment responses and clinical outcomes.
BACKGROUND: Although exposure to tobacco smoke has been associated with increased morbidity and mortality, cigarette smoking is still common in the asthmatic population. Induced sputum neutrophilia has been observed in asthmatic smokers, but the effects of regular smoking on their bronchial mucosa morphology remain to be defined. This study documents the inflammatory and remodelling features in bronchial biopsies of smoking compared with non-smoking asthmatics. METHODS: We analysed bronchial biopsies from 24 steroid-naïve young subjects with mild asthma: 12 non-smoking and 12 currently smoking subjects. In addition to airway morphology assessment, inflammation and remodelling were analysed by immunohistochemistry using antibodies against CD3, CD68, major basic protein, neutrophil elastase, and tryptase. Expression of the cytokines IL-4, IL-5, IL-8, IFN-gamma, transforming growth factor-beta, and TNF was determined by in situ hybridization. RESULTS: Compared with non-smoking asthmatic subjects, smoking asthmatics' bronchial mucosa showed squamous cell metaplasia, in addition to increased expression of subepithelial neutrophil elastase, IFN-gamma, and intraepithelial IL-8. CONCLUSIONS: Smoking status modifies morphological and inflammatory processes in young subjects with mild asthma. The changes may possibly affect asthma treatment responses and clinical outcomes.
Authors: Mark Spears; Charles McSharry; Rekha Chaudhuri; Christopher J Weir; Carl de Wet; Neil C Thomson Journal: PLoS One Date: 2013-08-09 Impact factor: 3.240
Authors: René Maximiliano Gómez; Víctor Hugo Croce; Mario Emilio Zernotti; Juan Carlos Muiño Journal: World Allergy Organ J Date: 2021-01-17 Impact factor: 4.084
Authors: Maria G Belvisi; Katie Baker; Nicole Malloy; Kristof Raemdonck; Bilel Dekkak; Michael Pieper; Anthony T Nials; Mark A Birrell Journal: Respir Res Date: 2018-05-10